>>28598489Yellow's the best genwun version. Pikachu can't really beat Brock, so you need to capture something that can. It's up to you, if you want to keep using Pika or not. I usually end up using it until I beat the E4, just because it keeps the game challenging and there aren't very many other Electric-types worth using until way later.
Yellow has tougher gym leaders and E4 than Red or Blue.
Gary/Blue's Eevee's evolution is determined by how you fare in the first two battles against him. If you win both, he gets a Jolteon. If you lose the first one and lose/skip the second one, he'll get a Vaporeon. If you win the first battle and skip/lose the second one, he'll get Flareon. I think his Jolteon is most powerful by a long shot, so if you want the most challenge, aim for that.
